JPH10176259A - Cutting tool made of surface coated cemented carbide excellent in chipping resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool made of a surface coated cemented carbide excellent in chipping resistance and showing excellent wear resistance over a long period. SOLUTION: This cutting tool made of a surface coated cemented carbide is obtd. by vapor-depositing the surface of a cemented carbide substrate composed of WC base cemented carbide or TiCN series cermet with a single hard coating layer or plural ones composed of either or both of (Ti, Al, An)N and (Ti, Al, Sn)CN respectively expressed by the formula of (Tia Alb Snc )N and the formula of (Tia Alb Snc )Cd N1-d where, by atom, (a) is 0.2 to 0.6, (b) is 0.1 to 0.79, (c) is 0.01 to 0.3, a+b+c=1 and (d) is 0.01 to 0.5} by the average layer thickness of 2 to 20μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has excellent chipping resistance, so that even when intermittent cutting of steel is performed at high speed, for example, there is no chipping (small chipping) on the cutting edge and excellent wear resistance. Coated cutting tool made of surface-coated cemented carbide (hereinafter referred to as coated cemented carbide tool)
It is about.

[0002]

2. Description of the Related Art Conventionally, for example, an arc ion plating apparatus, which is a kind of physical vapor deposition apparatus schematically shown in FIG.
In the state heated to a temperature of ° C., an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which a Ti-Al alloy having a predetermined composition is set, and at the same time, a nitrogen gas as a reaction gas and Alternatively, nitrogen gas and methane gas are introduced, while tungsten carbide (hereinafter referred to as WC)
A substrate made of a base cemented carbide or a titanium carbonitride (hereinafter, referred to as TiCN) cermet (hereinafter, collectively referred to as a cemented carbide substrate) is subjected to, for example, a condition in which a bias voltage of -120 V is applied. On the surface of the cemented carbide substrate, for example, as described in JP-A-62-56565, a composite nitride of Ti and Al [hereinafter, (Ti, A
l) Indicated by N] and composite carbonitride [hereinafter, (Ti, A
l) Indicated by CN], to produce a coated cemented carbide tool by depositing a single or multiple hard coating layer composed of one or both of them, with an average layer thickness of 2 to 20 μm. Are known.

[0003]

On the other hand, in recent years, high performance and high output of a cutting device have been remarkable, and there is a demand for labor saving and energy saving of the cutting process. Although there is a tendency, in the case of the above-mentioned conventional coated cemented carbide tools, although excellent wear resistance is exhibited in continuous cutting and interrupted cutting under normal cutting conditions, especially when interrupted cutting of steel etc. is performed at high speed In the present invention, chipping easily occurs in the cutting edge due to insufficient toughness of (Ti, Al) N and (Ti, Al) CN constituting the hard coating layer. is there.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above viewpoint, (Ti, Al) N and (Ti, Al) constituting the hard coating layer of the conventional coated cemented carbide tool described above.
Al) focused on CN, result of research to achieve this toughness improvement, by which the by containing Sn, the composition _{formula: (Ti a Al b Sn c} ) N, and the composition formula: (Ti _a Al _b Sn _c ) C _d N _1-d (where a: 0.2 to 0.6, b: 0.1 in atomic ratio)
~ 0.79, c: 0.01 ~ 0.3, a + b + c = 1,
d: 0.01 to 0.5), Ti, Al and Sn represented by
[Hereinafter, represented by (Ti, Al, Sn) N]
And composite carbonitride [hereinafter, (Ti, Al, Sn) CN
The hard-coated layer is formed of one or both of the above-mentioned (Ti, Al, Sn) N and (Ti, Al, Sn) C.
Since N has excellent toughness while maintaining excellent wear resistance, chipping will occur on the cutting edge even if the intermittent cutting is performed at high speed as well as continuous cutting of steel, for example. Instead, a study result was obtained that exhibited excellent wear resistance over a long period of time.

The present invention has been made based on the results of the above-mentioned research, and it has been proposed that the surface of a cemented carbide
The single layer or multilayer hard coating layer to be deposited with an average layer thickness of [mu] m, the composition _{formula: (Ti a Al b Sn c} ) N, and the composition _{formula: (Ti a Al b Sn c} ) C d N 1- _d , (However, in atomic ratio, a: 0.2 to 0.6, b: 0.1
~ 0.79, c: 0.01 ~ 0.3, a + b + c = 1,
d: 0.01 to 0.5), (Ti, Al, S)
n) A coated cemented carbide tool having excellent chipping resistance, comprising one or both of N and (Ti, Al, Sn) CN. In the coated cemented carbide tool of the present invention, a titanium nitride (hereinafter referred to as TiN) layer having a golden color of 0.1 to 1 in order to facilitate identification before and after use.
It is preferable to deposit an average layer of μm on the surface of the hard coating layer.

Next, (Ti, Al, Sn) N and (T) constituting the hard coating layer of the coated cemented carbide tool of the present invention.
The reason why the composition ratio (atomic ratio) of (i, Al, Sn) CN is limited as described above will be described. That is, the above (Ti, A
In (l, Sn) N and (Ti, Al, Sn) CN, the constituent components Ti and Al coexist and have an effect of improving the wear resistance. When it is less than 0.2 and Al: less than 0.1, the desired excellent wear resistance cannot be ensured, while, for any of Ti and Al, the proportions are Ti: 0.6 and Al: 0. If it exceeds 0.79, the toughness is reduced, and chipping is likely to occur on the cutting edge.
3 to 0.5, Al: 0.1 to 0.79, preferably 0.
3 to 0.7. In addition, Sn, which is also a component,
Has the effect of improving toughness and preventing chipping from occurring on the cutting edge, but if the ratio is less than 0.01, the desired effect of improving toughness cannot be obtained. If it exceeds, the hardness of the layer itself sharply decreases, and it becomes impossible to secure the excellent wear resistance provided by Ti and Al.
０．３0.3, preferably 0.05０．０５0.2. Further, since the C component in (Ti, Al, Sn) CN has an effect of improving hardness, (C, Ti, Al, Sn)
CN has a relatively high hardness as compared with the above (Ti, Al, Sn) N, but in this case, if the ratio of the C component is less than 0.01, a predetermined hardness improving effect cannot be obtained. If the ratio exceeds 0.5, the toughness rapidly decreases, so the ratio of the C component is set to 0.01 to 0.5, preferably 0.1 to 0.45. The reason why the average layer thickness of the hard coating layer is set to 2 to 20 μm is that if the layer thickness is less than 2 μm, the desired wear resistance cannot be secured, while if the layer thickness exceeds 20 μm, the cutting edge The reason why the average thickness of TiN deposited on the surface of the hard coating layer is set to 0.1 to 1 μm is that the thickness is less than 0.1 μm. No clear coloration is possible, while the desired golden color is due to the fact that a layer thickness of up to 1 μm is sufficient.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the coated cemented carbide tool of the present invention will be specifically described with reference to examples. WC powder having an average particle diameter of 1 to 3 μm,
A TiC powder, a TaC powder, an NbC powder, a ZrC powder, and a Co powder are prepared.
C: 84%, TiC: 2%, TaC: 4%, NbC: 1
%, ZrC: 3%, and Co: 6%, and wet-mixed in a ball mill for 72 hours, and dried.
Press molding into a green compact at a pressure of 1.5 ton / cm ² ,
This green compact is sintered in a vacuum at a temperature of 1420 ° C. for 1 hour, and after sintering, the cutting edge portion is subjected to honing processing of R: 0.06 to obtain ISO standard / SPMN 120408.
A cemented carbide substrate A made of a WC-based cemented carbide having the above-mentioned chip shape was formed. In addition, as raw material powders,
TiCN having an average particle size of ２2 μm (by weight, TiC
/ TiN = 50/50) powder, WC powder, TaC powder,
NbC powder, ZrC powder, Mo powder, Co powder, Ni powder, and C powder were prepared, and these raw material powders were added in weight%.
With TiCN: 72%, WC: 4%, TaC: 8%, Nb
C: 0.5%, ZrC: 1%, Mo: 6%, Co: 4.
5%, Ni: 3%, and C: 1% were blended, wet-mixed with a ball mill for 24 hours, dried, and dried.
The green compact is press-molded at a pressure of 1 ton / cm ² , and the green compact is heated to 1550 ° C. in a nitrogen atmosphere of 10 torr.
For 1 hour, and after sintering, add R:
Applying honing process of 0.04, ISO standard, CNM
A cemented carbide substrate B made of TiCN-based cermet having a chip shape of G120408 was formed.

Next, these cemented carbide substrates A and B were respectively loaded into an arc ion plating apparatus shown in FIG. 1, while Ti—Al— alloys having various component compositions were used as cathode electrodes (evaporation sources). A Sn alloy, a Ti-Al alloy, and metal Ti were mounted, and the inside of the apparatus was evacuated to 1 × 1
While maintaining the vacuum at 0 ^-5 torr and heating the inside of the apparatus to 400 ° C. with a heater, the cemented carbide substrate was subjected to −80 V
Then, an arc discharge is generated between the cathode electrode and the anode electrode while introducing a nitrogen gas or a nitrogen gas and a methane gas as a reaction gas into the apparatus, whereby the cemented carbide substrate A , B, on each surface, a hard coating layer having a composition and an average layer thickness shown in Tables 1 to 4 is formed, whereby the coated hard metal tools 1 to 18 of the present invention and the conventionally coated hard metal tools 1 to 1 are formed. 4 were each manufactured.

[0009] Of the various coated cemented carbide tools obtained as a result, the coated cemented carbide tools 1 to 9 of the present invention and the conventional coated cemented carbide tools 1 and 2 are as follows: Work material: length of JIS SNCM431 Dry high-speed intermittent cutting test of alloy steel under the following conditions: 4 bars with longitudinal grooves at equal intervals, cutting speed: 240 m / min, feed: 0.2 mm / rev, depth of cut: 1.5 mm, cutting time: 10 minutes In addition, for the coated cemented carbide tools 10 to 18 of the present invention and the conventionally coated cemented carbide tools 3 and 4, a work material: JIS SCr415H, a longitudinally-elongated round bar with three longitudinal grooves, a cutting speed, : 350m / min, Feed: 0.2mm / rev, Depth of cut: 1mm, Cutting time: 10 minutes, Dry high-speed intermittent cutting test of alloy steel was performed. Measurement It was. The measurement results are shown in Tables 2 and 4.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

From the results shown in Tables 1 to 4, all of the coated cemented carbide tools 1 to 18 of the present invention show excellent wear resistance in high-speed interrupted cutting of steel, and the wear condition of the cutting edge is also reduced. In contrast to the normal condition, conventional coated cemented carbide tools 1 to 4 cause chipping at the cutting edge in high-speed interrupted cutting of steel due to insufficient toughness of the hard coating layer, and the cutting time is relatively short. It is clear that the service life is reached. As described above, the coated cemented carbide tool of the present invention has the above (Ti, Al, Sn) N and (Ti, Al, S) constituting the hard coating layer.
n) Since CN has excellent toughness and high hardness, for example, not only high-speed continuous cutting of steel but also high-speed intermittent cutting of steel, which is a cutting process under more severe conditions, does not generate chipping on the cutting edge, It exhibits excellent wear resistance over an extremely long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an arc ion plating apparatus.

Claims (2)

[Claims] 1. The surface of a tungsten carbide-based cemented carbide substrate or a titanium carbonitride-based cermet substrate has a thickness of 2 to 20 μm.
Hard coating layer, the composition formula of the average layer alone is deposited to a thickness or multiple _{layers: (Ti a Al b Sn c} ) N, and the composition _{formula: (Ti a Al b Sn c} ) C d N 1-d (However, a: 0.2 to 0.6, b: 0.1 in atomic ratio)
~ 0.79, c: 0.01 ~ 0.3, a + b + c = 1,
d: 0.01 to 0.5), Ti, Al and Sn represented by
A cutting tool made of a surface-coated cemented carbide having excellent chipping resistance, comprising a composite nitride and / or a composite carbonitride. 2. The surface of a tungsten carbide-based cemented carbide substrate or a titanium carbonitride-based cermet substrate has a thickness of 2 to 20 μm.
Hard coating layer, the composition formula of the average layer alone is deposited to a thickness or multiple _{layers: (Ti a Al b Sn c} ) N, and the composition _{formula: (Ti a Al b Sn c} ) C d N 1-d (However, a: 0.2 to 0.6, b: 0.1 in atomic ratio)
~ 0.79, c: 0.01 ~ 0.3, a + b + c = 1,
d: 0.01 to 0.5), Ti, Al and Sn represented by
Characterized in that a titanium nitride layer having an average thickness of 0.1 to 1 μm is formed on the hard coating layer on the hard coating layer. Surface-coated cemented carbide cutting tool with excellent chipping resistance.